Prokarium's ZH9 Shows 91% Freedom-from-Relapse in Phase 1/1b Trial for Non-Muscle Invasive Bladder Cancer
Key Insights
Prokarium (search)'s bacterial immunotherapy ZH9 demonstrated 91% freedom-from-relapse at 12 months in heavily pretreated non-muscle invasive bladder cancer patients in the Phase 1/1b PARADIGM-1 trial.
The treatment showed excellent safety with no dose-limiting toxicities or Grade ≥3 drug-related adverse events reported among 22 patients who received at least one dose.
ZH9 offers a significant convenience advantage over current BCG therapy, requiring only 4-5 administrations per year compared to up to 18 catheterizations with standard treatment.
Prokarium (search) announced positive interim results from its Phase 1/1b PARADIGM-1 trial of ZH9, a bacterial immunotherapy for non-muscle invasive bladder cancer (NMIBC), demonstrating a 91% freedom-from-relapse rate at 12 months with an excellent safety profile. The data were presented at the American Urology Association (AUA26) Annual Meeting.
Strong Efficacy Signal in Heavily Pretreated Population
The PARADIGM-1 trial (NCT06181266) evaluated ZH9 in recurrent intermediate-risk and high-risk NMIBC patients. Among patients who reached the 12-month study endpoint, 10 of 11 patients (91%) remained free from disease relapse, representing a significant clinical outcome in this heavily pretreated population.
"These data demonstrate ZH9 as a universally applicable treatment for patients," said Dr. Josefin-Beate Holz, Prokarium (search)'s Chief Medical Officer. "As the treatment is very well tolerated and is showing impactful outcomes for early and BCG-non-responsive patients alike, it opens up the potential for ZH9 to be a transformative bladder saving treatment."
Favorable Safety Profile
The safety analysis included 22 patients who received at least one dose of ZH9. Only 6 patients (27%) experienced treatment-related adverse events, all of which were mild or moderate and transient. Notably, no grade 3 or higher toxicities, dose-limiting toxicities, or drug-related serious adverse events were observed throughout the study.
Addressing Treatment Burden
Current NMIBC treatment with BCG requires up to 18 catheterizations in the first year, which significantly impacts patient compliance and outcomes. ZH9 offers a substantial improvement in convenience, requiring only 4-5 administrations per year.
"There is a clear and urgent need to move beyond BCG," said Ibs Mahmood, CEO of Prokarium (search). "The current treatment burden—requiring up to 18 catheterisations in the first year—detrimentally impacts real-world compliance and patient outcomes. Patients deserve a therapy that is not only effective and safe, but also more convenient, and we believe ZH9, reducing this to just 4–5 administrations per year, could be a game changer."
Next Steps
Based on these encouraging results, Prokarium (search) plans to advance ZH9 into a larger Phase 2 study. The expanded trial will evaluate the treatment across a broader range of patient populations, including intermediate-risk and high-risk patients, as well as those with carcinoma in situ (CIS).
ZH9 represents a new class of bacterial immunotherapy designed to deliver broad and durable immune responses. The investigational treatment is being developed as an intravesical therapy for preventing recurrence in non-muscle invasive bladder cancer, with the PARADIGM-1 study having completed enrollment across multiple centers in the United States.